Black holes are cosmic objects formed from the remnants of massive stars that have undergone gravitational collapse. They possess such intense gravitational fields that even light cannot escape from them once it crosses a boundary called the event horizon. This phenomenon arises because the mass of the collapsed star is concentrated into an infinitely dense point known as a singularity.

The impact of black holes on their surroundings is profound. Nearby stars and other matter can be drawn into a swirling disk called an accretion disk before falling into the black hole. This process releases enormous amounts of energy in the form of X-rays and other radiation. Some black holes also eject powerful jets of particles at near-light speeds, influencing the dynamics of their galactic neighborhoods.

On a larger scale, supermassive black holes found at the centers of galaxies, like the one in our Milky Way, play a crucial role in galactic evolution. They regulate star formation by heating and expelling gas, influence the orbits of nearby stars, and are believed to have shaped the formation and growth of galaxies throughout cosmic history. In essence, black holes are not only enigmatic cosmic entities but also significant players in shaping the structure and dynamics of the universe.